Wildcat Creek Landuse History 1750-1800: Native Landscape

Impact Map — pre-1800


Watershed View — ca. 1800

To observe Wildcat Creek in this era, we might follow the deepwater channel along the northeast end of the Potrero toward the mouth of the Creek, as the Huchiun, returning from the Bay in tule balsas, would have. The channel curves to the north through the mudflats, passing several small islands indicative of recent erosion of the marsh. It shows a pattern of spartina and pickleweed transitioning to scirpus and tules as the influence of freshwater increases.

Crossing the native grasslands of the alluvial plain, Wildcat Creek passes numerous shellmounds, particularly around the large laguna between the two creeks. Fish caught both in the Bay and the creeks are processed here for local consumption and trade. Near the first shellmound along Wildcat Creek, we reach the upper extent of the tides and the beginning of the narrow riparian forest, the only trees of the alluvial plain. Continuing upstream, the Creek splits, with the older overflow channel to the south marking the boundary of present-day Davis Park. Trails lead along the Creek to the Potrero, to marsh ponds (for salt harvest and waterfowl hunting) and channels, and to the shellmounds at Ellis Landing and the town of Stege.

Where the Creek turns south, it passes the large shellmound and ceremonial center of the area, located at a lagoon in a "sink" at the end of a remnant channel of Wildcat Creek. The Creek then intersects the main road of the Richmond plain (now San Pablo Avenue), which the Spanish explorers followed into the Huchiun lands, passes the shellmounds and village at Alvarado Park, and enters the Canyon. The Canyon, like the plain, is much more open than in years to come. Regular burning by the Huchiun prevents encroachment of brush and woodland, except in the more sheltered ravines and north-facing slopes. Woodland is most dense in the narrow Lower Canyon, giving way to more brushland where the Canyon widens, and open areas at the top. Several trails cross the Canyon, and springs are common.

Wildcat Creek Landuse History 1800-1850: Ranchero Landscape

Approaching the mouth of Arroyo Chiquito (Wildcat Creek) from La Bahia de San Pablo in 1850, one observes several changes. Sediment from recent erosion of San Pablo and Wildcat Creek has buried over 100 acres of marsh in alluvial sediment. As a result, San Pablo Creek has filled its old bed that independently connected it to the bay and captured and widened a small slough that connects to Wildcat Creek.

At the convenient juncture of Arroyo Chiquito, Arroyo Grande (San Pablo Creek), and the receiving marsh slough, an Embarcadero has been built, enabling transfer of cattle products to San Francisco and more distant markets. As we follow Wildcat Creek across the flatlands, it passes just north of Juan Jose Castro's adobe, built with an unusual cellar which elevated the house 3.5 ft above ground, presumably to avoid flooding. Continuing upstream, we pass the original adobe, placed near the perennial laguna and built onto the earlier Mission Dolores ranch headquarters. Small gaps in the riparian forest are noted near the adobe, probably the first removal of riparian timber or signs of vegetation loss due to bank erosion.

The grasslands of the plain and Canyon — now grazed with cattle, sheep and horses — have undergone major changes in species composition and ecology, with deep-rooted perennials replaced by shallow-rooted annuals. The drought, which seemed to start at the time of the Spanish contact, has broken with the floods of 1832 (see page 9). Wildcat Creek is no longer referred to as Arroyo Seco.

After more than a decade during which the landscape was essentially abandoned, Rancho San Pablo is in full swing. Several thousand cattle graze the plain and the grassy hillsides of the Canyon. Despite the cattle, the area of brush and woodland has expanded in response to increased moisture conditions, greatly reduced fire frequency, and the combined absence of fire and cattle in the early part of the century. Brush expansion is most notable in areas of active or recent landslides.

Wildcat Creek Landuse History 1850-1900: Agricultural Landscape

By 1900, further changes in the Watershed are evident. Beginning at the Bay outlet of Wildcat Creek, we see a sequence of adjustments. The deepwater channel through the mudflats has shifted and is now directed away from the Potrero, between an expanded marsh island and the accreting front edge of the small remnant marsh. In a successful attempt to extend his title from the Alluvial Plain to the Potrero, a local resident has constructed levees around the perimeter of the marshland. The levees significantly reduce tidal flow to the marsh, drying up the narrow point between the Potrero and the mainland.

Most of the wider sloughs in the remaining marsh have filled in, indicating the effects of reduced tidal prism, increased sediment load from the Watershed, and hydraulic mining debris from the Sierra Nevada. The Creek's route through the marsh has been diverted to a more direct connection to Castro Slough near the landing, perhaps to help keep the slough open. The lower reach of the Creek has avulsed alternate channels and a straighter mainstem channel, probably as a result of increased sediment supply. The bulge of sediment at the bottom of the alluvial fan has continued to expand. Most dramatically, by 1895, San Pablo Creek has abandoned the meanders connecting it to Wildcat Creek and now flows directly into San Pablo Bay; 50 acres of willows have rapidly re-colonized the vicinity of the former channel. With the reduction of tidal prism, the riparian corridor along Wildcat Creek has rapidly extended nearly a mile downstream.

On the Alluvial Plain, farming has replaced grazing in many areas, especially along the Creek. San Pablo City Hall is located near the original adobe, and the first two railroad bridges have been built.

In the Canyon, brush and woodland have generally continued to expand, but on the west side brush has rapidly decreased by removal of dairy cattle and increased landslide activity. More roads lead to the Canyon and along parts of the Creek, but there are substantial gaps where no direct road is available. Good trout fishing on Wildcat Creek is noted in the national 1877 Sportsman's Gazetteer.

Wildcat Creek Landuse History 1900-1950: Urban Landscape

Viewing Wildcat Creek from San Pablo Bay on a low tide in 1950, one would see vastly expanded mudflats that cover nearly twice their 1900 area. Most of the diked baylands of the previous period have been filled; yet, ironically, the area of fully-tidal marshlands has increased. Where there is no fill, the tides have washed away nearly all traces of the earlier levees, and over 100 acres of new marsh has aggraded at the mouth of San Pablo Creek. The entry to Wildcat Creek now follows a deepwater shipping channel dredged through the marsh to serve the oil refinery located on the Potrero and former marshland. Turning east towards Wildcat Creek from the shipping channel, the slough passes a remnant levee and row of fishing shacks.

On the Alluvial Plain, agriculture has expanded bayward to use the new alluvial sediment deposited over the salt marsh, and the Creek channel has, naturally or by human influence, straightened below the railroad tracks. A large gap in riparian forest has appeared between 23rd and Church Streets. Except for along the lowest reaches of Wildcat and San Pablo Creeks, urban development has replaced nearly all of the earlier farming and ranching. Most of this change has taken place during a short period; about two-thirds of the development occurred during 1940-1945. Along with the housing, an urban forest has begun to grow.

Activity in the Canyon has also been intense, leading to numerous new trails and roads. Large areas have been planted in eucalyptus or pine plantations, and the dams for Jewel Lake and Lake Anza have been constructed. With the creation of Tilden Regional Park, the upper part of the Canyon has been removed from grazing. Fires, which had been fairly common along the urban edge of the Canyon, are now more actively suppressed. While most of the Upper Canyon is now protected from urban development, some housing, and associated urban trees, have entered the Canyon along the southwest edge.

Wildcat Creek Landuse History 1950-2000: Modern Landscape

During the period 1950-2000 we observe a large reduction in mudflat acreage as a result of both erosion and filling. The shipping channel at the mouth of Wildcat Creek has been enclosed, along with much of the remaining marshland, to store oil production materials.

The route of the Creek into the marsh has been changed through recent flood control projects that include a sediment catchment basin on Wildcat Creek. Immediately adjacent to Wildcat Creek lies the sole remnant of the earlier flower nurseries on the Wildcat Creek bottomlands. Industrial, residential and commercial development has covered most of the remaining flatlands to the north and northeast, with Hilltop Mall a prominent feature. The urban forest has matured in the older parts of town. A local sewage treatment plant and garbage landfill have filled portions of the marsh. Little or no accretion of marshland has occurred in the vicinity of Wildcat Creek or San Pablo Creek during this period.

New gaps in the riparian forest along the Alluvial Plain are evident, near Highway 80 for example, but it should be noted that some earlier gaps have filled in with new vegetation.

In the Canyon, the area of open grassland has continued to decrease as brush and woodland expand. The growth of new brushland is noticeable both in the upper, ungrazed part of the Canyon, and in some still-grazed areas, such as Havey Canyon. Similar changes can be seen in the undeveloped parts of the Potrero. With the addition of more housing in the Upper Canyon, and concomitant fire concerns, areas have been set aside for intensive vegetation management.